Thanks for trusting me to share all of that. That helps fill in more of the picture for me.
By all means, I agree that T may be part of this picture, especially as you're still getting used to it. But it also sounds like you're saying impulsivity has been an issue for you in general, not just around sex. I'm with you that feeling shame about sex and sexuality isn't a good thing and is something that you'll want to see what you can do to start changing. More on that in a second.
Have you ever seen a mental healthcare professional about the impulsivity, or been evaluated for ADHD (which yep, you're right, could also be an issue)? It doesn't sound like you have: if not, is that something you can access? If you can. I think that would be good for you, and probably the one of the best next steps here.
I can think of some other next steps, too, though, including things you can do if there's a waiting period for those evaluations. Can you and your partner make some very hard-limit agreements? And maybe set up some environments around them to help yourselves? For instance, how about when your Mom is home, you agree not to be sexual, period, but to engage in/explore other parts of your relationship instead, and put yourself in places in the house where being sexual isn't an option? How about sitting down and making a list of all the limits like this you want/need and then coming to the table with them and making some agreements and figuring out what adjustments you might need to make to make holding yourselves to them more attainable for y'all?
In terms of the shame, I want to say a few things that I hope might help you get a start on letting some of that go. Having a lot of or frequent desire for sex (what some people call a high sex drive) isn't anything to be ashamed of. That also doesn't control us or make us do things we don't want to. I don't think that that is likely much of the picture here save that when you are doing sexual things that you don't feel right about, it feels less awful to you because of that desire, that's all. Do you know what I mean?
Even if you are having a hard time learning to deal with sexuality and impulsivity, that *still* isn't anything to be ashamed of, just like it wouldn't be anything to be ashamed of if you were on the other side of this particular spectrum with low desire and low responsiveness to sexual opportunities, you know? It's so easy to forget what bullshit the messaging we all have inherited that the desire for more sex (or more food, or more rest, or more anything else our culture had very selectively deemed bad) is automatically more shameful is, and how much it can really get us twisted.
Learning what you're learning and adjusting to the things you're adjusting to isn't a shameful process, it's just a human one. I think if you can start to make some changes, that should help with the shame, but my hope is that you can recognize that even before you can do that, or while you are, you STILL do not have anything to feel ashamed of, and can start letting some of that shame go. <3
Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has. - Margaret Mead